https://leetcode.cn/problems/ones-and-zeroes/

class Solution {
public:
    int findMaxForm(vector<string>& strs, int m, int n) {
        int len=strs.size();
        vector<vector<int>> dp(m+1,vector<int>(n+1));

        for(int i=1;i<=len;i++)
        {
            //统计0 和 1
            int a=0,b=0;
            for(auto x:strs[i-1])
                if(x=='0') a++;
                else  b++;

            for(int j=m;j>=a;j--)
            {
                for(int k=n;k>=b;k--)
                {
                    dp[j][k]=max(dp[j][k],dp[j-a][k-b]+1);
                }
            }
        }
        return dp[m][n];

    }
};